Disturbances in GABA function have been hypothesized to contribute to the symptoms of schizophrenia and alcoholism. The purpose of this study is to compare cortical GABA levels in schizophrenic patients, recently detoxified alcoholics, and healthy subjects. GABA levels are measured using a novel non-invasive technique, magnetic resonance spectroscopy. Subjects complete a screening day and three test days. On each test day, a randomly selected region (frontal cortex, temporal cortex, occipital cortex) and an adjacent white matter control region are assessed.